Abstract: Based on the characteristics of multiple input multiple output (MIMO) radar virtual array, a new combinatorial method based on minimum redundancy array is proposed for optimal design of transmitting and receiving (Tx/Rx) antenna arrays to make the MIMO radar virtual array be minimum redundancy, which can utilize the limited number of array elements to obtain a large aperture. In addition, for a given total number of Tx/Rx antenna elements, how to allocate the number of Tx and Rx antenna elements to obtain the optimal virtual array has also been studied in this paper. Both analytical and simulation results show that the proposed array design method is simple and easy to implement, has high array element utilization rate, and can be used for MIMO radar with a large number of array elements.